Bug #557

Debian Bug report logs - #438224libexiv2-0: Wrong values on exposure time

Added by Mark Purcell over 13 years ago. Updated over 5 years ago.

Target version:
Start date:
Due date:
% Done:


Estimated time:
1.00 h



File (6.5Mb):;filename=crw_4353.crw;att=1;bug=438224

Result:$ exiv2 crw_4353.crw
File name : crw_4353.crw
File size : 5029136 Bytes
MIME type : image/x-canon-crw
Image size : 3072 x 2048
Camera make : Canon
Camera model : Canon EOS 300D DIGITAL
Image timestamp : 2007:08:15 22:16:04
Image number : 143-4353
Exposure time : 1/2147483647 s
Aperture : F10
Exposure bias :
Flash :
Flash bias : 0 EV
Focal length :
Subject distance: Infinite
ISO speed : 400
Exposure mode : Manual (M)
Metering mode :
Macro mode : (0)
Image quality : RAW
Exif Resolution : 3072 x 2048
White balance : Auto
Thumbnail : None
Copyright :
Exif comment :

Additional information:

From: Valerio Passini <>
Subject: libexiv2-0: Wrong values on exposure time
Date: Thu, 16 Aug 2007 10:41:59 +0200

Package: libexiv2-0
Version: 0.15-1
Severity: normal

Hi All,

I've a Canon 300D and I've shot some pictures during night of fireworks in
bulb mode exposure time (I have opened the shutter manually for 3-4
secs). I have used ufraw to convert the .crw files in .jpeg images and
in those the exposure time is wrong like 1/2147483648 (!).
In the other images with exposure time of 1/150 secs and below all is correct.

-- System Information:
Debian Release: lenny/sid
APT prefers unstable
APT policy: (700, 'unstable'), (600, 'testing'), (1, 'experimental')
Architecture: i386 (i686)

Kernel: Linux (PREEMPT)
Locale: LANG=it_IT@euro, LC_CTYPE=it_IT@euro (charmap=ISO-8859-15)
Shell: /bin/sh linked to /bin/bash

Versions of packages libexiv2-0 depends on:
ii libc6 2.6.1-1 GNU C Library: Shared libraries
ii libgcc1 1:4.2.1-4 GCC support library
ii libstdc++6 4.2.1-4 The GNU Standard C++ Library v3
ii zlib1g 1: compression library - runtime

Versions of packages libexiv2-0 recommends:
pn exiv2 <none> (no description available)

-- no debconf information



Updated by Pedro CĂ´rte-Real over 6 years ago

This bug is still present in 0.23 at least. It seems that Exif.Photo.ExposureTime is being interpreted incorrectly for values >1. The sample provided returns 1/0 for that value. Exiftool reports 128 which may very well also be wrong.


Updated by Robin Mills about 6 years ago

  • Subject changed from Debian Bug report logs - #438224 libexiv2-0: Wrong values on exposure time to Debian Bug report logs - #438224libexiv2-0: Wrong values on exposure time
  • Description updated (diff)
  • Target version set to 53

I'm going to mark this for review. I'm not convinced there is a bug here. Let me explain. Exposure is being stored as rational 1/0.

866 rmills@rmillsmbp:~ $ exiv2 -pv -g Exp ~/Downloads/crw_4353.crw 
0x829a Photo        ExposureTime                Rational    1  1/0
0x0014 CanonCs      ExposureProgram             Short       1  4
867 rmills@rmillsmbp:~ $ exiv2 -pt -g Exp ~/Downloads/crw_4353.crw 
Exif.Photo.ExposureTime                      Rational    1  1/0 s
Exif.CanonCs.ExposureProgram                 Short       1  Manual (M)
$ 871 rmills@rmillsmbp:~ $ exiv2 -g Exp ~/Downloads/crw_4353.crw 
Exif.Photo.ExposureTime                      Rational    1  1/0 s
Exif.CanonCs.ExposureProgram                 Short       1  Manual (M)
872 rmills@rmillsmbp:~ $ exiftool ~/Downloads/crw_4353.crw | grep -i exposure
Exposure Compensation           : 0
Flash Exposure Compensation     : 0
Auto Exposure Bracketing        : Off
Exposure Time                   : 128
Canon Exposure Mode             : Manual
869 rmills@rmillsmbp:~ $ 
It seems to me that the camera stored 1/0 in the image and there's no bug to be fixed.

I'm going to link this to #933 which is a discussion about how to present the "interpreted" value of a rational.


Updated by Robin Mills over 5 years ago

  • Status changed from New to Assigned
  • Assignee set to Robin Mills

This issue has been in the database for 8 years and nobody else has requested progress with this matter. So, unless you engage to persuade me to keep this matter alive, it will be closed on April 30 as "no longer needed/wanted".


Updated by Robin Mills over 5 years ago

  • Category changed from exif to withdrawn
  • Status changed from Assigned to Closed
  • Target version changed from 53 to 0.26
  • % Done changed from 0 to 100
  • Estimated time set to 1.00 h

Also available in: Atom PDF